Buggy code:
public class PasswordStrength extends LessonAdapter { private Map < String , PasswordStrength . Password > passwords = new TreeMap < String , PasswordStrength . Password > ( ) { } ; private class Password { String password ; String timeUnit ; String answer ; private String explanation ; public Password ( String password , String timeUnit , String answer , String explanation ) { } } private boolean checkSolution ( WebSession s ) throws ParameterNotFoundException { } protected Element createContent ( WebSession s ) { } public List < String > getHints ( WebSession s ) { } private static final Integer DEFAULT_RANKING = new Integer ( 6 ) ; protected Integer getDefaultRanking ( ) { } protected Category getDefaultCategory ( ) { } public String getInstructions ( WebSession s ) { <START_BUG> String instructions = "The<seq2seq4repair_space>accounts<seq2seq4repair_space>of<seq2seq4repair_space>your<seq2seq4repair_space>web<seq2seq4repair_space>application<seq2seq4repair_space>are<seq2seq4repair_space>only<seq2seq4repair_space>as<seq2seq4repair_space>save<seq2seq4repair_space>as<seq2seq4repair_space>the<seq2seq4repair_space>passwords.<seq2seq4repair_space>" + ( ( "For<seq2seq4repair_space>this<seq2seq4repair_space>exercise,<seq2seq4repair_space>your<seq2seq4repair_space>job<seq2seq4repair_space>is<seq2seq4repair_space>to<seq2seq4repair_space>test<seq2seq4repair_space>several<seq2seq4repair_space>passwords<seq2seq4repair_space>on<seq2seq4repair_space><a<seq2seq4repair_space>href=\"https:////howsecureismypassword.net\"<seq2seq4repair_space>target=\"_blank\">https:////howsecureismypassword.net<//a>.<seq2seq4repair_space>" + "<seq2seq4repair_space>You<seq2seq4repair_space>must<seq2seq4repair_space>test<seq2seq4repair_space>all<seq2seq4repair_space>6<seq2seq4repair_space>passwords<seq2seq4repair_space>at<seq2seq4repair_space>the<seq2seq4repair_space>same<seq2seq4repair_space>time...<br>" ) + "<b><seq2seq4repair_space>On<seq2seq4repair_space>your<seq2seq4repair_space>applications<seq2seq4repair_space>you<seq2seq4repair_space>should<seq2seq4repair_space>set<seq2seq4repair_space>good<seq2seq4repair_space>password<seq2seq4repair_space>requirements!<seq2seq4repair_space><//b>" ) ; <END_BUG> return instructions ; } public String getTitle ( ) { } public Element getCredits ( ) { } }

Fix:
String instructions = "The<seq2seq4repair_space>accounts<seq2seq4repair_space>of<seq2seq4repair_space>your<seq2seq4repair_space>web<seq2seq4repair_space>application<seq2seq4repair_space>are<seq2seq4repair_space>only<seq2seq4repair_space>as<seq2seq4repair_space>save<seq2seq4repair_space>as<seq2seq4repair_space>the<seq2seq4repair_space>passwords.<seq2seq4repair_space>" + ( ( "For<seq2seq4repair_space>this<seq2seq4repair_space>exercise,<seq2seq4repair_space>your<seq2seq4repair_space>job<seq2seq4repair_space>is<seq2seq4repair_space>to<seq2seq4repair_space>test<seq2seq4repair_space>several<seq2seq4repair_space>passwords<seq2seq4repair_space>on<seq2seq4repair_space><a<seq2seq4repair_space>onclick=\"window.open(this.href,\'_blank\');return<seq2seq4repair_space>false;\"<seq2seq4repair_space>href=\"https:////howsecureismypassword.net\">https:////howsecureismypassword.net<//a>.<seq2seq4repair_space>" + "<seq2seq4repair_space>You<seq2seq4repair_space>must<seq2seq4repair_space>test<seq2seq4repair_space>all<seq2seq4repair_space>6<seq2seq4repair_space>passwords<seq2seq4repair_space>at<seq2seq4repair_space>the<seq2seq4repair_space>same<seq2seq4repair_space>time...<br>" ) + "<b><seq2seq4repair_space>On<seq2seq4repair_space>your<seq2seq4repair_space>applications<seq2seq4repair_space>you<seq2seq4repair_space>should<seq2seq4repair_space>set<seq2seq4repair_space>good<seq2seq4repair_space>password<seq2seq4repair_space>requirements!<seq2seq4repair_space><//b>" ) ;